1. Field of the Invention
This invention relates to a bicycle pedal, more particularly to a pedal device for fastening a cyclist's shoe to a bicycle pedal shaft.
2. Description of the Related Art
Devices of the type which permit easy positioning and rapid disengagement of a shoe on a pedal without deliberate intervention are known in the prior art. FIGS. 1 and 2 respectively show an exploded and a cross-sectional view of an assembled conventional pedal device that comprises mainly a cleat 1 to be fixed beneath the sole of a shoe and a pedal body 2 to be mounted rotatably on a conventional pedal shaft 21 for retaining the cleat 1. The cleat 1 has a curved insert piece 12 which is received releasably by a claw portion 22 of the pedal body 2 and a substantially curved rear end portion 13 with a pair of curved flanges 131 disposed symmetrically at two sides. The pedal body 2 has a pair of rearwardly movable jaw members 25 which resiliently receive the pair of curved flanges 131 and allow the disengagement of the cleat 1 from the pedal body 2 only when the heel of the foot makes an upward lateral thrust in a direction away from the pedal shaft 21.
A drawback of the above-mentioned pedal device is that only a pair of identical spring members 3' is used to mount the movable jaw members 25 at the rear portion of the pedal body 2. Thus, when the rear end of the cleat 1 is compressed so as to be engaged with the retaining jaw members 25, the retaining jaw members 25 provide weak engagement therebetween.